Pulse transformer for transmitting and receiving signal

ABSTRACT

A pulse transformer for transmitting and receiving signal is disclosed. In order to manufacture a second coil into windings containing a condenser component, the pulse transformer for transmitting and receiving signal to the present invention comprises a first condenser electrode, a second condenser electrode, faced to the first condenser electrode; a dielectric or an insulator, positioned between the first and second condenser electrodes and joined to the first and second condenser electrodes; and first and second lead lines, each connected to the first and second condenser electrodes, for performing a function of power lines in order to transmit the signal or being connected to the power lines. According to the present invention, by employing a condenser component as the input and output portions of the transformer, signal attenuation and noise effect of the transmission lines can be deeply reduced by raising the internal impedance, when transmitting and receiving a pulse signal.

TECHNICAL FIELD

The present invention relates to a pulse transformer for transmittingand receiving signal, in particular to a pulse transformer fortransmitting and receiving signal for reducing signal attenuation andnoise effects on transmission lines by employing a transformer having acondenser component at signal input/output portions and getting highimpedance.

BACKGROUND ART

Power Line Communications (PLC) technology is for communication byadopting power lines, which provide power, as a medium and carryingvoice and data on a signal of hundreds of kHz to tens of MHz. When thePLC technology is applied, home networking, information home appliances,management of power line network, etc., are possible and their relatedindustries are expected to provide new services and activate thepotential markets. In particular, high speed access technology applyingthe PLC and low speed control technology using the home network arenoted as the next generation communication technology by domestic andexternal communication companies or power service companies.

Since the PLC employs the power lines as the medium, it is difficult tobe realized in contrast with the data transfer using communicationcables or optical fibers. In particular, the PLC needs to overcomeunique circumstance such as heavy loads, interference, noise, variableimpedance and signal attenuation, etc., and transfer the data throughthe limited power lines. If the power lines are adopted as acommunication medium, technology for removing various kinds of noiseshould be provided.

For this, a transformer for transmitting and receiving signal isemployed as an intermediate transfer means in the process of datatransmission and reception for short and long distances. However,typical structure of the transformer has a limit for long distancetransmission when the data transfer is performed in tens of MHz orhundreds of MHz unit. Namely, since the internal impedance is realizedand limited by the numbers of first and second coil winding times in theconventional pulse transformer, the above described technicaldifficulties are generated in the data transfer for hundreds of meters.

DISCLOSURE OF INVENTION

It is, therefore, an object of the present invention to provide a pulsetransformer for transmitting and receiving signal for reducing signalattenuation and noise effects on transmission lines by employing thetransformer having a condenser component to signal input/output portionsto minimize the number of coil winding times and get high impedance,when impedance matching in an electronic circuit or an insulatingstructure in a part of the circuit as well as long distance transmissionand reception of an electric signal are needed.

To achieve the above object, according to the present invention, thereis provided a pulse transformer for transmitting and receiving signalcomprises a coil for being input power; and first and second condenserelectrodes for being positioned apart from the coil and inducedelectromagnetically, being one-bodied but electrically separated fromeach other by a dielectric or an insulator, performing a function ofpower lines in order to transmit a signal or being formed each lead lineconnected to the power lines. Preferably, the first and second condenserelectrodes are wound in a coil shape.

To achieve the above object, according to the other aspect of thepresent invention, there is provided a pulse transformer fortransmitting and receiving signal comprising a first coil at a firstcoil side, and a second coil at a second coil side for being inducedelectromagentically by the first coil, in order to manufacture thesecond coil into windings containing a condenser component, the secondcoil comprising a first condenser electrode; a second condenserelectrode, faced to the first condenser electrode; a dielectric or aninsulator, positioned between the first and second condenser electrodesand joined to the first and second condenser electrodes; and first andsecond lead lines, each connected to the first and second condenserelectrodes, for performing a function of power lines in order totransmit the signal or being connected to the power lines.

At this time, the first and second condenser electrodes are in a lineform or in a plate form.

Here, the dielectric or the insulator is comprised selectively on anexposure side of the first condenser electrode or the second condenserelectrode in order to prevent the first and second condenser electrodesfrom being short when the first and second condenser electrodes arewound in a coil shape.

BRIEF DESCRIPTION OF DRAWINGS

The above objects, features and advantages of the present invention willbecome more apparent from the following detailed description when takenin conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic diagram illustrating that a pulse transformer fortransmitting and receiving signal is comprised at transmission andreception sides on the power lines.

FIG. 2 is an equivalent circuit diagram of the pulse transformer fortransmitting and receiving signal at the transmission side.

FIG. 3 is an equivalent circuit diagram of the pulse transformer fortransmitting and receiving signal at the reception side.

FIG. 4 is an equivalent serial consonant circuit diagram of A.

FIG. 5 shows a configuration of the pulse transformer for transmittingand receiving signal according to a first embodiment of the presentinvention.

FIG. 6 shows a configuration of the pulse transformer for transmittingand receiving signal according to a second embodiment of the presentinvention.

FIG. 7 shows a structure of B in the second embodiment.

FIG. 8 shows the other structure of B in the second embodiment.

FIG. 9 is a schematic diagram illustrating an applied example of thepulse transformer for transmitting and receiving signal of the presentinvention.

BEST MODE FOR CARRYING OUT THE INVENTION

A preferred embodiment of the present invention will now be describedwith reference to the accompanying drawings.

FIG. 1 is a schematic diagram illustrating that a pulse transformer fortransmitting and receiving signal is comprised at transmission andreception sides on the power lines. Referring FIG. 1, a pulsetransformer 10 for transmitting and receiving signal is positioned at atransmission side in a predetermined region and a pulse transformer 20for transmitting and receiving signal is positioned at a reception sidein the other predetermined region. A typical alternating voltage of220V, 60 Hz is used between them. To be sure, a voltage provided togeneral houses and plants from a transformer substation can be more thanthat.

FIG. 2 is an equivalent circuit diagram of the pulse transformer fortransmitting and receiving signal at the transmission side. ReferringFIG. 2, the pulse transformer for transmitting and receiving signal atthe transmission side comprises a first coil L1 at a first coil side, asecond coil L2 and a third coil L3 at a second coil side. The secondcoil L2 and third coil L3 at the second coil side are closely separatedand coupled to be a capacitor C1. FIG. 3 is an equivalent circuitdiagram of the pulse transformer for transmitting and receiving signalat the reception side. Referring FIG. 3, the pulse transformer fortransmitting signal and receiving signal at the reception side comprisesa sixth coil L6 at the first coil side, a fourth coil L4 and a fifthcoil L5 at the second coil side. The fourth coil L4 and the fifth coilL5 at the second coil side are closely separated and coupled to be acapacitor C2.

FIG. 4 is an equivalent serial consonant circuit diagram of A. ReferringFIG. 4, a Q value at the output end, namely a voltage gain, can beobtained by inducing a mixed serial resonance value, X_(L)+X_(C), from avoltage induced from the condenser itself in a predetermined frequencyby making the condenser formed in the second coil side.

FIG. 5 shows a configuration of the pulse transformer for transmittingand receiving signal according to a first embodiment of the presentinvention. Referring FIG. 5, a dielectric 104 is formed between a firstcondenser electrode 100 and a second condenser electrode. A first leadline 106 and a second lead line 108 are formed at the first and secondcondenser electrodes 100, 102, respectively. A copper line 110 is woundaround the first and second condenser electrodes 100, 102 in apredetermined interval like a coil. Consequently, the coil, which windsthe transformer once and is formed of the copper line, performsbehaviors corresponding to the first and second coil sides of thetransformer.

The behaviors according to the present invention are described withaccompanying drawings of FIG. 1 to FIG. 5.

When an analog signal is transmitted between the pulse transformers 10,20 for transmitting and receiving signal at the transmission andreception sides in FIG. 1, a voltage becomes induced to the second coilside C1 in proportion to the number of winding times in case that asignal voltage is applied to the first coil L1 of FIG. 2. At this time,according to a structure of FIG. 5, since both electrode ends showtotally 1 winding effect, a voltage corresponding to the 1 windingbecomes induced. Capacity of the condenser is as small as 100 pF andinternal impedance is as much as several MΩ. A signal received in thepulse transformer 20 for transmitting and receiving signal at thereception side of FIG. 1 induces a voltage in the sixth coil L6 of FIG.3 as an induced voltage.

As shown in FIG. 1, two lines between the pulse transformers 10, 20 fortransmitting and receiving signal at the transmission and receptionsides are the power lines using typical alternating power 220V.Accordingly, when a high frequency signal is transmitted and receivedbetween the pulse transformers 10, 20 for transmitting and receivingsignal at the transmission and reception sides, C1 and C2, thecondensers of the pulse transformers 10, 20 of transmitting andreceiving signal at the transmission and reception sides, respectively,obtain durability of the pulse transformers basically as much asinternal pressure and capacity of an insulator. The voltage generateddirectly inside the condenser is proportion to an impedance of thefollowing equation. $\begin{matrix}{X_{C} = \frac{1}{2\pi\quad{fC}}} & (1)\end{matrix}$

According to the above equation, the impedance is output easier as thefrequency goes higher. Consequently, the larger impedance is output forthe alternating voltage of 220V, 60 Hz. Actually, when the highfrequency is carried on the alternating voltage of 220V, the largeimpedance is required like the following equation for a parallelconfiguration in 220V, 60 Hz.X _(L)=2πfL  (2)

If reactance is relatively high, a function of the high frequency signalbecomes very small and then the function as a pulse transformer forinputting and outputting a signal becomes lost. If the pulse transformerof the present invention is employed, the internal impedance between thepulse transformers 10,20 for transmitting and receiving signal at thetransmission and reception sides becomes several MΩs. Consequently, thefollowing typical side effects can be improved.

That is, signal attenuation can be minimized. When the internalimpedance of a first portion, the pulse transformer 10 for transmittingand receiving signal at the transmission side, gets higher, the signaltransmission gets easier for long distance. Also, the voltage can betransmitted to the pulse transformer 20 for transmitting and receivingsignal at the reception side of FIG. 1, namely C2 of FIG. 3, with noisebeing relatively lowered along the long distance. This is the mostimportant point of the power line communications. Namely, this can havethe strong signal maintained without attenuation by maintainingrelatively long transmission distance, not affected by noise accompaniedwith the AC lines.

FIG. 6 shows a configuration of the pulse transformer for transmittingand receiving signal according to a second embodiment of the presentinvention. Referring FIG. 6, the pulse transformer for transmitting andreceiving signal comprises a first coil of the first coil side, a secondcoil and a third coil of a second coil side, formed around a bedded ironcore. The present second embodiment is to apply the first and secondcondenser electrodes of FIG. 5 to a typical configuration of thetransformer, and to apply them as a coil type to the second transformerin comparison with the one of FIG. 5. The coupled materials of the firstand second condenser electrodes are wound in appropriate frequencieseach according to various uses. They also have forms of pair or aplurality of inputs and outputs.

FIG. 7 shows a structure of B in the second embodiment Referring FIG. 7,the structure of B, being able to be applied to the second coil side ofFIG. 6, has long plate type metals, first and second metal plates 200,202, faced each other, a dielectric 204 or an insulator 204 inserted asthe same form as the two metal plates 200, 202 between them, first andsecond lead lines 206, 208 connected to the two metal plates 200, 202,respectively. Then, the same shape as the coil wound around the beddediron core in FIG. 6 is formed. When winding it in a coil type, thedielectric 210 or insulator 210 can be additionally joined to oneexposed side of the two metal plates 200, 202, because the two metalplates 200, 202 can be short according to the winding method.

FIG. 8 shows the other structure of B in the second embodiment.Referring FIG. 8, a first metal plate 300, a second metal plate 302, adielectric 304 or an insulator 304, a first lead line 306 and a secondlead line 308 are formed similarly or the same as each one of FIG. 7.The only difference is that the second embodiment has larger area perunit length in comparison with that of FIG. 7. Namely, it has length T,long enough to wind the bedded iron core. As shown in FIG. 7, thedielectric 310 or insulator 210 can be additionally joined to oneexposed side of the two metal plates 300, 302, because the two metalplates 300, 302 can be short according to the winding method.

The behaviors according to the embodiments are described withaccompanying drawings of FIG. 6 to FIG. 8.

The embodiments have structures for raising the internal impedance ofthe second coil side of the pulse transformer for transmitting andreceiving signal absolutely, without regarding the number of windingtimes of the first and second coils. For example, in case of highfrequency of tens of MHz, an induced reactance value of 6.2 kl can beobtained when 40 times of coil winding around a perforated bobbin with10 mm diameters results in 100 mH inductance value.

On the contrary, when manufacturing a transformer having theconfiguration as shown in FIG. 7 or 8 according to the presentinvention, the transformer can obtain relatively higher impedance underthe same conditions. That is, as shown in FIGS. 7 and 8, when forming acondenser consisted with dielectrics or insulators between two planeconductive films, winding the second coil around the condenser like thecoil which winds 40 times around the perforated bobbin with 10 mmdiameters, and then installing electrodes at both ends of the conductivefilms, a voltage, proportional to the number of winding times, ischarged to and discharged from the condenser repeatedly. Simultaneously,the induced reactance corresponding to the number of winding times ofthe coil becomes realized in a single object like a composite circuithaving X_(L)+X_(C). At this time, due to a characteristic of dischargeof the condenser even to an infinite external resistor, the second coilside output structure having the internal impedance of several or moreMΩ becomes realized. Their equivalent values N₂ and C₁ to the ones ofFIG. 4 are decided by the following equation. $\begin{matrix}{{\tau\quad r} = \frac{1}{2\pi \times {LC}}} & (3)\end{matrix}$

As the equation of (3), a serial resonant frequency according to apredetermined frequency is calculated and consequently a voltage gain isamplified like the following equation. $\begin{matrix}{Q = {\frac{VL}{V} = {\frac{VC}{V} = {\frac{Wr}{R} = {\frac{1}{WrcR} = {\frac{1}{R} \times \frac{L}{c}}}}}}} & (4)\end{matrix}$

Since a signal of the second coil side can be larger than the one of thefirst coil side and the value of being proportional to the number ofwinding times, it can be implemented as an amplifier for thepredetermined frequency.

FIG. 9 is a schematic diagram illustrating an applied example of thepulse transformer for transmitting and receiving signal of the presentinvention. Referring FIG. 9, the pulse transformer is formed by windingthe first coil of the first coil side N1 around the perforated bobbin 40times, winding the one-bodied second and third coils of the second coilside N2 around the perforated bobbin 40 times too, allowing the internalelectricity to tolerate the internal pressure at the alternating voltageof 1000V and then forming a condenser of 100 pF. If several MHzfrequency is applied to the first coil side N1 on the power lines of thealternating voltage of 220V, 60 Hz, any other high frequency signaltolerating the alternating voltage can be applied to the alternatingpower lines as applications because the internal pressure of theinsulator of the second coil side N2 connected to P1 and P2 issufficient to.

While the invention has been shown and described with reference tocertain preferred embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims.

As described above, the pulse transformer for transmitting and receivingsignal according to the present invention employs a condenser componentas the input and output portions of the transformer so that signalattenuation and noise effect of the transmission lines can be deeplyreduced by raising the internal impedance, when transmitting andreceiving a pulse signal. In addition, it can be ensured highreliability to a signal, being smaller than 1V, as well as be extremelyeasily installed in the power lines by processing the second side coilas a condenser with a function of tolerating high voltage.

1. A pulse transformer for transmitting and receiving signal comprising:a coil for being input power; and first and second condenser electrodesfor being positioned apart from the coil and inducedelectromagnetically, being one-bodied but electrically separated fromeach other by a dielectric or an insulator, performing a function ofpower lines in order to transmit a signal or being formed each lead lineconnected to the power lines.
 2. The pulse transformer according toclaim 1, wherein the first and second condenser electrodes are wound ina coil shape.
 3. A pulse transformer for transmitting and receivingsignal comprising a first coil at a first coil side, and a second coilat a second coil side for being induced electromagnetically by the firstcoil, in order to manufacture the second coil into windings containing acondenser component, the second coil comprising: a first condenserelectrode; a second condenser electrode, faced to the first condenserelectrode; a dielectric or an insulator, positioned between the firstand second condenser electrodes and joined to the first and secondcondenser electrodes; and first and second lead lines, each connected tothe first and second condenser electrodes, for performing a function ofpower lines in order to transmit the signal or being connected to thepower lines.
 4. The pulse transformer according to claim 1, wherein thefirst and second condenser electrodes are in a line form.
 5. The pulsetransformer according to claim 1, wherein the first and second condenserelectrodes are in a plate form.
 6. The pulse transformer fortransmitting and receiving signal according to claim 2, wherein thedielectric or the insulator is comprised selectively on an exposure sideof the first condenser electrode or the second condenser electrode inorder to prevent the first and second condenser electrodes from beingshort, when the first and second condenser electrodes are wound in acoil shape.
 7. The pulse transformer according to claim 3, wherein thefirst and second condenser electrodes are in a line form.
 8. The pulsetransformer according to claim 3, wherein the first and second condenserelectrodes are in a plate form.
 9. The pulse transformer fortransmitting and receiving signal according to claim 3, wherein thedielectric or the insulator is comprised selectively on an exposure sideof the first condenser electrode or the second condenser electrode inorder to prevent the first and second condenser electrodes from beingshort, when the first and second condenser electrodes are wound in acoil shape.